Liquid heater



F. J. SMlTH LIQUID HEATER Dec. 15, 1964 2 Sheets-Sheet l Filed April 4, 1963 F- J. SMITH LIIQUID HEATER Dec' 15) 2 Sheets-shee: 2

Filed. April 4) 1963 United States Patent O 3,`l61,178 LIQUID HEATER Frank If. Smith, L7352. lliirnekiln Pite, Philadelphia 38, a. Filed Apr. 4, 19253, Ser. Ne. 279,5'74 4 Ciaiins. (Cl. lii-31% This invention relates to a liquid heater, particularly to a domestic type liquid heater wherein a liquid in tubes is heated by projected fuel flames, as from an oil burner, commonly referred to as a hot water boiler; and has for an object the provision of improvements in this art.

lIn my Patent No. 2,736,298, February 28, 1956, there is show-n a ilame-heated liquid heater having a liquid header and depending liquid tubes surrounding a fire box. The present invention is an iinprovement on that general type of heater.

One of the particular objects of the present invention is to provide a liquid beating device of improved characteristics for higher efiiciencies, maxirnum safety, and minimum requirements of labor and material for construction.

Another object is to provide, by a novel construction, a means for obtaining rapid liquid flow in the heat transfer tubes by the use of a flow direction bafrle in conjunction with forced liquid circulation, as by a pump. This feature not only increases the efciency of operation by greater absorption of heat but also eliminates damage to the tubes by overheating which occurs when inadequate cooling exists due to insufiicient liquid circulation.

Another object is to provide a simple means for quick replacement of the entire combustion Chamber refractory.

Another object is to provide a self-closing explosion door to relieve excess pressure in the combination chamber such as might occur in the event of faulty delayed ignition or other cause.

Another object is to provide means for viewing the entire combustion chamber during operation and permitting visual examination of the flame pattern, the surface of the refractory combustion chamber in its entirety, and the portions of the tubes exposed to the direct heat of combustion.

Another object is to provide means for introducing.7 cleaning equipment into the gas passages for easy removal of soot accumulations without the necessity for disassembling any portion of the heater.

Another object of the invention is to provide a small and simple arrangement of liquid tubes and fire box to obtain greater efiiciency in construction and heat exchange.

Another object is to provide improved flow of hot combustion gases over the tubes.

Another object is to provide an improved fire box construction and arrangement.

Another object is to provide an effective plural burner arrangement to assure a continued Supply of heat in case one burner should fail.

The above and other objects of the invention, as well as various features of novelty and advantages, will be apparent from the following description of an exemplary embodiment, reference being made to the accompanying drawings, wherein:

``FIG. 1 is a vertical longitudinal section and elevation of a ilame heated liquid tube heater embodying the invention;

FIG. 2 is a horizontal section taken on the line 2 -2 of PIG. l;

PIG. 3 is an enlarged partial section in the zone 3 of FIG. 1;

FIG. 4 is a partial vertical transverse section taken on the line 4-4 of PIG. l;

PIG. 5 is a reduced perspective view of the heater with the outer protective insulated casing removed and with parts cut away in places;

FIG. 6 is a perspective view of a fire box alone;

`PIG. 7 is a vertical longitudinal section and elevation of a modified form of heater having dual opposed burners.

The liquid heater, commonly referred to as a hot water boiler and sometimes referred to as a furnace, comprises a base plate Itl having upturned peripheral ilanges 11 upon which are supported the vertical plates 12, 13, 14, 15 which form a main peripheral ring enclosure and frame for the boiler. The side and rear plates 12, 13 and 14- could be formed as a single bent member; but Conveniently are formed of separate plates welded together along their vertical edges.

The side plates 12 and '14 are provided with lateral vertical flanges le and the front plate 15 is detachably secured to the ilanges, as by bolts or screws 17. This provides quick and convenient access to the interior and allows ready repair or exchange of the fire box WlL'ch is generally designated by the numeral 18.

A space is left between the base fianges li and the frame plates 117,, }13, 14, l15 and this space may be sealed by suitable material 19, such as fire clay or the like.

At the top, the main frame, comprised, as stated, of the vertical plates 12,13, 14, 15, supports a horizontal tube plate Ztl, preferably welded to the upper end of the vertical frame plates except the front one 15 Which is removable; and the tube plate 20 supports a plurality of depending liquid tubes 21. The tubes 21 are fitted in holes formed in the tube plate and are sealed tightly thereto, as by expansion or welding or both. In assembling, they may be tack welded to the lower side of the tube plate to hold them in position and later expanded in the tube holes.

The tubes 21 are closed at the bottom end, as by plates or plugs 22 secured therein or thereon in any convenient way, as by welding for example.

The liquid tubes form a peripheral ring enclosure, here rectangular, around the fire box and hot gas Chamber thereabove. The front and rear sets of liquicl tubes are short to end above the upper edge of the fire box 1.8; and the side sets of tubes are longer and extend down below the bottom of the fire box. They are provided at the lower ends with lugs 25 Welded thereto which support the fire box assembly. The tubes are spaced apart to provide for the Circulation of combustion gases between them.

Plates `26, 27, 23, 29 are secured to the outer sides of the tubes 21, as by welding at spaced points thereto, to form enclosures of approximately the same lengths as the tubes for coniining and directing hot gases. A small space is left between the plates 12, 13, 14, 15 forming the frame shell and the interior plates 26, 27, 28, 29.

The fire box 13 eomprises an open-topped metal box 39 lined with heat insulating slabs, as of pre-formed fire clay. There is a bottom plate or slab 31, side slabs 32 and 34, a rear or target slab 33, and a front slab 35 having a hole 36 therethrough for the tube 37 of an oil burner unit (not shown). The front side of the box 30 is provided With a like opennig 38 for the burner tube 37. The front plate 15 of the main frame is provided with a tube 39, welded thereto, which surrounds the burner tube 37.

Above the tube plate 20 a header or liquid space is provided. Specifically, there are two liquid spaces 'or chambers, an outer space orchamber 4% for inflow or cooler liquid and an inner space or chamber 41 for outflow or hotter liquid. I

The outer liquid space 40 is ring-shaped and defined by the tube plate 20 at the bottom, by a cap plate 42 at the top, vby an outer peripheral shell plate 43 welded between the plates 20 and 42, and an inner'peripheral shell plate or baflie 44 welded between the upper end lower plates, or at least to one of them, intermediate the sides of the top openings of the liquid tubes 21.

The inner liquid space 41 is also ring-shaped or annular and defined by the lower and upper plates 20, 42, the bafile ring plate 44, and an inner tube 45 welded between'the plates 20 and 42 to constitute a si-ght, cleanout, and explosion vent opening 46. It is made quite large to serve all of these purposes. 1,.

A liquid inflow tube 50 is welded in an opening in the outer'ring plate 43; and a liquid outflow tube 51 is welded in the bafl'le ring plate 44.

A cap door 52, which may have a fire-resistant lining and, if desired, a clear pane, is hinged at 53 to the cap plate 42 for upward opening for access or explosion.

Liquid normally stands at a level below the cap plate 42, as shown, and air under pressure is maintained there- .above by an air vent tube 55 which is connected with the pressure air space of an expansion tank, not shown.

Hot gases from the fuel flame F 4flow upward over and between all of the liquid tubes 21 and downaround i tubes.

by the'same numerals. One such material is marketed as Cerafelt by Johns-Manville; another is marketed as 'fFilberfrax by Carborundum.

Another form of the invention is shown in FIG. 7, this form being arranged to use two fuel burners, which in the illustrated form are in opposed relationship With flames F', F' meeting at a parti-al medial target bafile wal-l 75 of the fire box` 18'. The burner tubes are designated as 37'. Here the smoke box 58' and smoke pipe 59' are placed at one side and at a higher elevation than in the first form; and two sight opening tubes with appurtenances are provided. There also may be two sets of liquidcirculating pipes 51', if desired. Other than noted,'the parts and Varrangement are the .same as the first form and like parts are designated by the same reference character With a prime (')4 added; I t is not necessary to enumerate all of the parts or to'apply all of the reference characters for a proper understanding of the modified form. v'

The sight tube 45, as stated, is of ample diameter to provide a full view of the flames from the top side and also provides a view of most of the inner sides of the The caps may be opened without danger while the burner is running sincethere is only a slight pressure inside the heater. The upwardly opening caps also provide relief in case of an explosion. 'I'he weight4 of the caps is adequ-ate to keep them closed while the burner isrunning. Thesight opening also provides ample space I for the insertion of tools or hoses for cleaning the inte- 56 beneath the fire box, thence through anopening 57 in the rearframe plate 13-into a smoke box 58 and V -smoke pipe 59 attached to the back of the plate 13, as by screws or bolts 60. i

An outer casing 65 with interior insulation 66 surrounds the main frame or casing, being spaced'therefrom as shown. The outer .casing will preferably 'be made in separate parts adapted to be secured together for quick assembly and separation, in particular the front panel being removable for access to or removal of the fire box; Vbut the details of this arrange'ment are omitted. The rear side of the outer casing has Van opening for the smoke pipe 59 and the water pipes 50 and 51; thefront side has an opening for the tube 39 and an annular insulated ring 67 secured thereto, as by screws 68; and the top has a hole for the sight opening and cap door 52 I witha closure cap 69 therefor hinged at '70.

The flow of hot gases, as already. described, is indicated by `ari-ows.

The flow of liquid is also indicated by arrows. Since theinner lsides of the tubes above and around the fire box are heated more than the outer sides, there is a tendency to produce a hydrostaticr flow upward on the inner side and downward on the outer side. The arrangement of the bale plate 44 above the top openings I of the tubes aids greatly in this d-irectional circulationV side, thus providing better exposure for heating as the liquid flows more slowly upward on the inner side.

The slabs or plates of refractory material which line the inside of the fire box are all relatively thick in the form shown in FIGS. l to 5. Such slabs maybe made I of fire clay. If more space. is needed in the fire'box it is possible to replace some or all of the thickr fire'clay slabs by plates of recently developed materials which have higher heat resistance to thickness than fire clays. FIG. 6 shows two thin plates 32' and 34' used'for the topportion of the narrowed thick s'ides of the fire box, all other parts being as in FIGS; 1-5 andV designated u and inserting a suction rior of the heater. In case a liquid material is used for cleaning, the base plate with its flanges forms a pan .for catc'hing the liquid. In the first form of FIGS. 1-5 it is possible to withdraw any liquid which accumulates in the pan by removing the smoke pipe (see FIG. 1) hose through the opening 57 into the pan.

It is thus seen that the invention provides .a compact, simple, inexpensive, convenient and very efiicent liquid heating unit which is easy to inspect, service and clean.

. While one ernbodiment of the invention has been descrrbed for purposes of illustration it Will be understood that there may be various'embodiments and modificatubesv being closed at the lower end; means above said tube plate defining a liquid space; an annular baflie plate in. saidr liquid space above and intermediate the Width of Vtubes and closes the space on the outer side of said enclosure sheet means against the flow of combustion gases; said liquid tubes being fully open and yfree from partition means inside to Vprovide for free Circulation of liquid therein down the covered cooler outer side which is not exposed to heating combustion gases-and up the heated inner side at any point along }the length where return flow is induced; the space vvithin said ring of tubes being fully open beneath said tube plate; and means defining outflow space f-or fuel combustion gases adjacent the lower end of said tubes.

2. A. liquid heater as set forth in claim l, in which said bafile plate is located nearer -the outer sides of said tube sheet holes than the innerside to provide more space 5 6 for upowing hot liquid than for doWnfloWing cold liquid. Referenees *Cted by the Examiner 3. A liquid heater as set forth in claim 1, in Which an UNITED STATES PATENTS enclosed passage is provided from the top through the inner liqud space into the open cornbuston gas space be- 45167 S/g Furman 122' 318 low the tube plate Within the ring of tubes, and a top 5 ak s oro mon closure for said enclosed passage.

4. A liquid heater as set forth in claim 1, in Which means are provided for supportim said fire box formnzr 7 means on the lower ends of the tubes on certain sides: ROBERT A' OLEARY, Prmmry Exammer' leaving one side open for the removal of the fire box 10 KENNETH Wl SPRAGUE, Exmninen forming means, and in Which the outfiow space for combustion gases is located below the fire box formng means.

1607325 8/52 Denker et al. 

1. A LIQUID HEATER, COMPRISING IN COMBINATION: A VERTICAL CIRCUMFERENTIAL SUPPORTING FRAME; A HORIZONTAL TUBE PLATE SECURED TO THE TUBE FRAME AT A DISTANCE ABOVE ITS LOWER END; SAID TUBE PLATE HAVING A PERIPHERAL RING OF TUBE HOLES NEAR BUT SPACED FROM ITS OUTER PEIRPHERY; A PLURALITY OF LIQUID TUBES SECURED IN THE HOLES OF THE TUBE PLATE AND EXTENDING DOWNWARD IN A RING THEREFROM; THE TUBES BEING CLOSED AT THE LOWER END; MEANS ABOVE SAID TUBE PLATE DEFINING A LIQUID SPACE; AN ANNULAR BAFFLE PLATE IN SAID LIQUID SPACE ABOVE AND INTERMEDIATE THE WIDTH OF SAID TUBE HOLES AND DIVIDING SAID LIQUID SPACE INTO INNER AND OUTER LIQUID SPACES; INLET AND OUTLET LIQUID FLOW PIPES CONNECTED RESPECTIVELY WITH SAID INLET AND OUTLET LIQUID SPACES; MEANS DEFINING A FIRE BOX BELOW SAID TUBE PLATE WITHIN SAID RING OF TUBES; ENCLOSURE SHEET MEANS CLOSELY SURROUNDING THE OUTER SIDE OF SAID LIQUID TUBES WHICH CONFINES FUEL COMBUSTION GASES WITHIN THE RING OF LIQUID TUBES AND CLOSES THE SPACE ON THE OUTER SIDE OF SAID ENCLOSURE SHEET MEANS AGAINST THE FLOW OF COMBUSTION GASES; SAID LIQUID TUBES BEING OPEN AND FREE FROM PARTITION MEANS INSIDE TO PROVIDE FOR FREE CIRCULATION OF LIQUID THEREIN DOWN THE COVERED COOLER OUTER SIDE WHICH IS NOT EXPOSED TO HEATING COMBUSTION GASES AND UP THE HEATED 